As Congress considers legislation addressing when and how law enforcement can track cell phone data, lawmakers in Maine are taking steps at the state level towards tightening restrictions. Last night, the Maine Senate approved a bill that requires law enforcement to get a warrant before tracking cell phone data. But what's being hailed as a victory for civil rights is seen as a defeat for public safety by opponents of the bill. They said if the bill is enacted, police will lose access to a valuable crime-solving tool.

Solving a crime is like a puzzle. Police gather bits of information that, when put together, tell a story about what happened. Using cell phone data to know the historic location of a suspect can be one of those key pieces of the puzzle. Take this case Democratic Senator Linda Valentino told her fellow senators the story of homicide in southern Maine where a man was murdered.

"The wife claimed an intruder broke into the house," Valentino said. "When detectives interviewed the wife the next day, her brother and a friend were at a house, and detectives were told they had just arrived from New York to comfort her."

But when police tracked the locations of the mens' cell phones, the data it revealed didn't match their story. Police were able to tell that the brother and friend had traveled through New York to Connecticut, Massachusetts, New Hampshire, and finally Maine, all on the same day as the homicide. Ultimately, they determined that all three conspired to kill the husband. Police did have to get a court order to get that cell phone location data. But under the bill passed by the Senate, law enforcement would have to take an extra step and get a a search warrant first. That, said Senator Valentino, significantly impedes investigations.

"Why is cell phone location data so important to law enforcement?" asked Valentin0. "One, to see if someone may have committed a crime, and the other is to eliminate people who probably didn't commit the crime because they were not near the crime scene or the victim at this period of time."

But there's a question of right to privacy and protection against unreasonable search and seizure here. Republican Senator Roger Katz, the sponsor of the bill, said existing law that requires a court order instead of a warrant is too low a threshold to ensure citizen's fourth amendment rights under the Constitution.

The bill includes an exception for emergency situations, such as a search for a missing child or in the event of a terrorist attack. Search warrants would not be needed in those cases. But Katz, who is an attorney, said it's time for the law to catch up with technology. Democratic Senator Seth Goodall, also an attorney, agrees. He said information about your location tells a lot more than just your whereabouts.

"In this day and age, where your cell phone, your smart phone, tells your whole life story," Goodall said. "The places you have been, to the foot. The places you have stopped. How long you have been there. The patterns of your behavior. And from all of that information, so much can be gleaned."

The Maine State Police, the Chiefs of Police, and Attorney General Janet Mills all oppose the bill, and Republican Senator David Burns, a former state trooper, voiced that opposition to the Senate. He said he's mystified about why this bill was even conceived.

"There are no complaints about abuse of this in this state," Burns said. "There's no abuse, no complaints from the third party people that keep these records, nor for any issues of abuse by the police or prosecutors office."

But just because there haven't been complaints in the past doesn't ensure that law enforcement won't abuse their access to this information, said Democratic Senator John Patrick. He points out that the bill includes a $134,000 fiscal note to fund two full time positions at the Attorney General's office to handle law enforcement requests for this cell phone data.

"That doesn't make sense," Patrick said. "How many hundreds of thousands of Mainers are they spying on if they're going to need two full-time people?"

Patrick said he doesn't want to take away from law enforcement's ability to catch criminals, but he also wants to protect Maine citizen's privacy. Patrick voted for the bill, along 19 other senators, along bipartisan lines. It has yet to be considered by the house.